Bisphosphonates, often prescribed to treat osteoporosis, can no longer be associated with lower rates of breast cancer, according to a new report in JAMA Internal Medicine.

However, a study in Cancer Research presents preliminary data indicating that nonsteroidal anti-inflammatory drugs (NSAIDs) may protect against recurrence of the disease in overweight and obese women.

JAMA Internal Medicine authors Trisha Hue, PhD, and colleagues described their analysis of data from two double-blind, placebo-controlled clinical trials in which women who received bisphosphonates had a slightly higher but statistically nonsignificant incidence of breast cancer.

One study of 6,459 U.S. women aged 55 years to 81 years revealed that the use of alendronate or placebo did not affect the proportion of women who developed breast cancer (1.8% and 1.5%, respectively).

In the other study, 7,765 women aged 65 years to 89 years from the United States, Canada, Asia, Europe, and South America were randomized to annual intravenous zoledronic acid or a placebo, and showed no difference in the development of breast cancer (0.87% and 0.77%, respectively).

In Cancer Research, Linda A. deGraffenried, PhD, and fellow investigators reported on their retrospective analysis of 440 breast cancer survivors.

Daily use of NSAIDs in women who had breast cancer positive for estrogen receptor α (ERα) and who had an average body mass index higher than 30 was associated with a 52% lower recurrence rate and a 28-month delay in time to recurrence than seen among women who did not use NSAIDs.

Approximately 81% of participants took aspirin, and the rest took another NSAID. Approximately 75% of breast cancers are ERα-positive, noted the researchers.